Sheet-feeding mechanism



Sept. 21, 1926:"

J. R. BLAINE SHEET FEEDING MECHANISM Filed May 5, 1924 Patented Sept. 21, 1926.

JOSEPH R. BLAINE, OAK PARK. ILLINOIS, ASSIGIiTOR TO MIEI-ILE PRINTING PRESS &: MANUFACTURING COMPANY, OF CHICAGO, ILLINOIS, A CORPORATION OF ILLINOIS.

Application filed May 3,

This invention relates to sheet feeding mechanism, and more particularly'to sheet grippers.

In some printing presses sheet material must be carried a relatively long distance and accordingly should bequite positively gripped to prevent the sheetmaterial from becomingdisengaged or displaced with respect to the grippers. However, when; the sheet has reached the position at which it is to be deposited and stripped from the grippers, it is necessary that the stripping be easily done without crimping the sheet material or in anywise adversely affecting the registration of the sheet. 7 Accordingly, one object of the present invention is to provide sheet feeder gripper mechanism in which the grippers may grip a sheet with a variable pressure so that during the main part of travel of the sheet, the grippers will have a relatively tight hold on the sheet, and at the point of deposit will have a relatively light hold on the sheet.

Another object of my invention is to provide simple, efiicient and reliable sheet feeder gripper mechanism adapted to meet the various requirements under service OOIld1" tions;

These and other objects are accomplished by means of the arrangement disclosed on the accompanying sheet of drawings, in whichv I I Figure l is a fragmentary side elevation. parts being in section, of a printing press embodying my invention, the grippers being in a relatively remote position with respect to the front guide means;

Figure '2 is a similar fragmentary side elevation of the gripper mechanism showing the gripper just at the point where it is about to reach the front guide and the fed sheet is to be stripped from the gripper, and showing means just about to become effective to lessen the hold of the gripper on said sheet; and V Figure 3 is a side elevation of the gripper mechanism on its return movement and showing the gripper with the parts arranged so that its gripping action is at a minimum and preparatory to being reset for a more positive gripping action.

The various novel features of the invention will be apparent from the following description and, drawings, and will be par- H t'i'cularly pointed out in the appended claims.

SHEET-FEEDING- MECHANISM.

1924. Serial No. 710,761.

trated in connection with a printing press having an impression cyllnder 10 to which sheet material is fed over a feed board 11. V The sheet material is temporarily arrested in its movement by front register guidesf.

only one of which, 12, is shown. The sheet material is fed to the front register by grippers and the-sheet stripped therefrom when the fed sheet passes into engagement with the front guides. v

The gripper herein illustrated includes a relatively stationary jaw-l3 secured to an arm 14 mounted on a support 15' and also includes a relatively "movable or pivotally mounted gripper jaw 16 which is pivotally mounted at 17 on the arm 14:. Normally the movable gripper jaw' 16 is held in en-; gagement with the relatively stationary gripper jaw 13 by a spring 18 coiled around a rod 19 which, at its lower end, is pivotally connected at 20 to the rear portion of the movable gripper jaw 16, the spring being compressed between a suitably adjustable abutment 21 on the rod '19 and a latch 22 pivotally mounted upon'the arm 14. As shown in Figures 1 and 2, and particularly in Figure 2, the latch 22 is held inan elevated position by a locking member 28 which also is pivotally connected to the arm 14:. The locking member'23 is normally held in such posi- I tion by a spring 24 wrappedaround a pin 25 and having one end engagingthe upper sur-. face of the arm 14 and the other end engaging theupper wall of the locking member 23. It

will be appreciated that if the latch 22 is permitted to swing from itselevated posi ert less pressure upon the relatively movable gripper jaw 16 than when the latch 22 isin its elevated position wherein the spring 18 is compressed an increased amount.

to grip a sheet with a considerable degree .100 As mentioned hereinabove, it is desirable v of pressure during the main feeding portion of the sheet and to relax said gripping pressure a given amount just-about the time when the sheet is to be stripped from the gripper. Accordingly, the'latch 22 should be elevated to compress the spring 18 duringthe greater portion of the feeding movement. of the sheet material and the latch 22 should occupy its lower position to decrease the holding effect of the spring at the point where the sheet is to be stripped from the gripper. As shown in Figure 2, the gripper is firmly holding theshe-et 26, the latch 22 being held in its elevated position by the locking member 23. In said figure, however,

' ward the front guide 12, the locking member 23 will be rotated in a clockwise direction until the latch 22 is freed from the looking I member, i hereupon under the tensionof the spring 18 the latch 22 wlll be forcedlnto its lowermost position, and as a result thereof the force with which the sheet is gripped between the gripper jaw will be relaxed so that the sheet may be readily stripped from the gripper jaws as the latter pass forwardly beyond the front guide 12.

Thereafter the gripper is given a return movement as shown in Figure 3 of the drawings, with the latch 22 still in its down position and it continues to occu y that pos tlon until the gripper reaches the position shown in Figure 1 wherein the latch 22 again is reset for increasing the compression of the spring for the purpose mentioned. For re setting the latch 22' any suitable abutment 29' is provided against which the latch is forced for raising the latter into a position so that the, locking member 28 under the in fluence of spring 24L may move under the latch 22 for 'releasably holding the latter in its elevated position.

It is my'intention tocover allmodifications of the invention falling within the spirit and scope of the following claims,

I claim: v

' 1. In sheet feeding mechanism, the combination. of gripperjaws, and means includ ing a releasably' mounted member carried by one of said jaws for automatically varying the gripping force of said? same jaws during the operation thereof. 7 v

2. In sheet feeding meeh anism, -.the combii nation of gripper members, and meansineluding, a. releasablymounted member carriedby one: of said. gripper members for antomatically varying the gripping. force of said same: gripper; members duringjthe operationthereof. I

S. Insh'eet feeding mechanism, ,the' combination of. gripper n'1embers,and .means for automatically varying the gripping force-of said same gripper members duringa feeding movement thereof and including a spring pjreseedalatch carried by one of said gripper members;

Y 5a. eefinisheet feeding mecii-anism the c'ombi nation of gripper jaws, and means whereby a sheet is yieldably gripped by said jaws with a certain yieldable pressure during part of the cycle of operation and with a different yieldable pressure during another part of said cycle of operation.

5, In sheet feeding mechanism, the combination of a stationary gripper jaw, a movable gripper jaw, a spring operative upon said movable gripper jaw, and means for normally varying the effectiveness of said spring for varying the gripping action of said j aw members during the operation thereof. I

6. In sheet feeding mechanism, the combination of relatively stationary jaw meniber, 'a relatively movable jaw member, means for yieldably pressing oneagainst the other for gripping purposes, and meansoperable upon said last mentioned means for varying the degree of yieldably gripping action.

7. In bination of relativelymovable gripper jaws, and means under certain conditions for yieldably preising said gripper awstogetlior with certain degree ofpressure and under other conditions for yieldably hold'ing said jaws together with a different degree 0f pressure. 8. In sheet feeding mechanism, the-combination of a relatively stationary gripper jaw, a relatively movable gripper jaw, pressure means operative upon 'saidrelati-vely n'iova-ble gripper jaw for pressing the latter against the relatively stationaryl gri'p'per jaw, and a latch by means of which the gripping force between said awe is varied 9. In sheet feeding mechanism, the combination of a relativelystationary gripper jaw, a relatively movable gripper jaw, a spring operative upon said relatively rnovable gripper aw for creating a gripper force between said jaws, a latch operative upon said spring for varying the gripping force between said jaws, and areleasable locking member operative upon saidlatch for holdingor releasing. the latter for varying the effect of said spring.

1'0. In sheet feeding mechanism forprinting presses, the combination of, a front guide, relatively stationary and movable gripper members, a spring operative upon said movable gripper member, a latch for compressing the spring a given amount for creating a given gripping force between said gripper members, a releasable locking'niember for holding said latch in a given position, and means operative upon. said lo cl'ririg member for releasing-said latch for varying the gripping force of said same gripper members adjacent sa idlguide.

Signed at Chicago, Illinois, this 8th day of April, 1924:. 

